Yes, I was one of those people. In fact, I used to think depression was a person's desperate cry for attention in my early teens, not actually accepting it is a real disorder. I've also been carefree and happy, which is why during my first depressive episode I knew there had to be something wrong. Things that I was so effortlessly able to do before had become the ultimate burden, school had became the most difficult thing in the world, and I'd spend 17 hours a day sleeping. As time progressed, things only worsened and I had to stop being in denial or I would have completely lost myself within the depression. I say this to say you owe yourself a better quality life. One where you enjoy yourself and things around you. Depression has the tendency to rob people of that and even the happiest of us are not exempt.